This invention relates generally to electrical test devices and, more particularly, to electrical test shunts for measuring current. Test shunts generally require some sort of mating terminals to connect the shunt to the circuit in which current is to be measured. The resistance of the shunt mating terminals greatly affects the resistance of the shunt and the accuracy of the current measurement. The amount of resistance added to the circuit is typically more than is acceptable to provide accurate current measurements. Furthermore, it is difficult to compensate for this additional resistance.
The prior art has not addressed the issue of providing a shunt element as an integral part of a junction box. Junction boxes are typically either two or three dimensional mechanical arrays of electrical conducting metal frets that typically join electrical wires with electronic modules within an electrical distribution system. The prior art has further failed to address the issue of providing a junction box having a shunt which can be coupled in a current loop of a circuit in a manner such that the terminal resistances of a voltage sensing apparatus are located outside of the current loop being monitored when the junction box and shunt are coupled in the circuit, to thereby prevent the terminal resistances from adversely affecting the accuracy of the current measurement calculated from the voltage measurement taken across the shunt.
Accordingly, it is a principal object of the present invention to virtually eliminate the affect of terminal resistance in the calculation of a load current by integrating a shunt in a junction box as part of an electrical conductor array.
It is an additional object of the present invention to provide a shunt in a junction box that provides a sufficiently accurate resistance necessary to accurately measure a voltage from which a load current may be calculated.
It is yet another objective of the present invention to provide a shunt formed integrally with a junction box, to thereby provide a single apparatus which performs all of the functions of a common junction box as well as providing a readily available shunt for accurate current measurements, and where the apparatus is economical to manufacture.